An LED driving circuit for driving an LED load including N LED strings, where N is a positive integer no less than 2, can include: (i) a power converter having a power switch; (ii) a constant current control circuit that controls a switching operation of the power switch such that the power converter generates a driving current for the LED load; (iii) N control switches respectively coupled in series to the N LED strings; (iv) a PWM signal generator configured to generate N color tuning PWM signals; and (v) a color tuning control circuit configured to output N switching control signals according to the N color tuning PWM signals, to control switching operations of the N control switches, to regulate a ratio of a current through each LED string of the LED load to the driving current, and to regulate the color temperature of the LED load.